1. Field of the Invention
A dispensing valve adapted to dispense fluent imaging materials used in electrostatographic copying machines, the valve being designed to be attached to the downwardly facing mouth of an inverted bottle containing such a material.
2. Description of the Prior Art
Dispensing valves are well known in the industry. It is a valve which customarily is attached to the mouth of a fluid-containing bottle when the bottle is erect, that is to say, when its mouth faces upwardly. At this time the valve is biased to closed position. The bottle then is inverted. No fluid will flow out of the bottle because the valve is biased to closed position. The bottle with the valve attached and in upside down position is placed on a support in conjunction with a machine in which the bottled fluid is designed to be employed. The support holds the bottle upside down. Within the receptacle an element engages an anchoring member of the dispensing valve to displace a valve plug upwardly and thereby open the valve. In one mode of use the dispensing valve remains open during its period of operation and will automatically dispense fluid, usually liquid, into the machine as a function of the prevailing hydrostatic pressures. In this mode the valve sometimes is referred to as a birdfeeder. Heretofore such a valve has constituted a plug mounted on a spindle and biased to closed position against a valve seat in the valve body. The plug frictionally engages the spindle. Movement of the plug off the spindle was prevented by a retainer ring. The degree of compression of the spring was fixed by the position of another retainer ring on the spindle. The two retainer rings had to be located on the spindle with a reasonable degree of precision in order to properly position the plug and to impart the proper degree of compression to the spring. Because several elements had to be manipulated during assembly of the components of the dispensing valve and because the plug and spring had to be correctly located, it has been necessary to assemble the parts of the valve with the aid of a jig. This has unduly raised the cost of assembly and unduly slowed the production line, both factors having tended to increase the production cost of the valve. The prior art birdfeeder valve is detailed in a later portion of this specification with relationship to a figure that shows the structure. In another mode of use the dispensing valve is intermittently opened and closed by a member, e.g., a flipper, that periodically presses up against the lower end of the spindle to lift the plug when a sensing element determines that additional fluid is required and allows the spindle and plug to drop either after a predetermined period of time or after the need for additional fluid has been supplied.